SDN Use Case: Content Filtering

K-12 schools face unique challenges with their IT infrastructure.  Their user base needs access to a large amount of information while at the same time facing restrictions.  While it does sound like some corporate network policies, the restrictions in the education environment are legal in nature.  Schools must find new ways to provide the assurance of restricting content without destroying their network in the process.  Which lead me to ask: Can SDN Help?

Online Protection

The government E-Rate program gives schools money each year under Priority 1 funding for Internet access.  Indeed, the whole point of the E-Rate program is to get schools connected to the Internet.  But we all know the Internet comes with a bevy of distractions. Many of those distractions are graphic in nature and must be eliminated in a school.  Because it’s the law.

The Children’s Internet Protection Act (CIPA) mandates that schools and libraries receiving E-Rate funding for high speed broadband Internet connections must filter those connections to remove questionable content.  Otherwise they risk losing funding for all E-Rate services.  That makes content filters very popular devices in schools, even if they aren’t funded by E-Rate (which they aren’t).

Content filters Continue reading

Why is Lync The Killer SDN Application?

The key to showing the promise of SDN is to find a real-world application to showcase capabilities.  I recently wrote about using SDN to slice education networks.  But this is just one idea.  When it comes to real promise, you have to shelve the approach and trot out a name.  People have to know that SDN will help them fix something on their network or optimize an troublesome program.  And it appears that application is Microsoft Lync.

MIssing Lync

Microsoft Lync (neè Microsoft Office Communicator) is a software application designed to facilitate communications.  It includes voice calling capability, instant messaging, and collaboration tools.  The voice part is particularly appealing to small businesses.  With a Microsoft Office 365 for Business subscription, you gain access to Lync.  That means introducing a voice soft client to your users.  And if it’s available, people are going to use it.

As a former voice engineer, I can tell you that soft clients are a bit of a pain to configure.  They have their own way of doing things.  Especially when Quality of Service (QoS) is involved.  In the past, tagging soft client voice packets with Cisco Jabber required setting cluster-wide parameters for all clients.  It Continue reading

SLAAC May Save Your Life

A chance dinner conversation at Wireless Field Day 7 with George Stefanick (@WirelesssGuru) and Stewart Goumans (@WirelessStew) made me think about the implications of IPv6 in healthcare.  IPv6 adoption hasn’t been very widespread, thanks in part to the large number of embedded devices that have basic connectivity.  Basic in this case means “connected with an IPv4 address”.  But that address can lead to some complications if you aren’t careful.

In a hospital environment, the units that handle medicine dosing are connected to the network.  This allows the staff to program them to properly dispense medications to patients.  Given an IP address in a room, staff can ensure that a patient is getting just the right amount of painkillers and not an overdose.  Ensuring a device gets the same IP each time is critical to making this process work.  According to George, he has recommended that the staff stop using DHCP to automatically assign addresses and instead move to static IP configuration to ensure there isn’t a situation where a patient inadvertently receives a fatal megadose of medication, such as when an adult med unit is accidentally used in a pediatric application.

This static policy does lead Continue reading

Moscone Madness

The Moscone Center in San Francisco is a popular place for technical events.  Apple’s World Wide Developer Conference (WWDC) is an annual user of the space.  Cisco Live and VMworld also come back every few years to keep the location lively.  This year, both conferences utilized Moscone to showcase tech advances and foster community discussion.  Having attended both this year in San Francisco, I think I can finally state the following with certainty.

It’s time for tech conferences to stop using the Moscone Center.

Let’s face it.  If your conference has more than 10,000 attendees, you have outgrown Moscone.  WWDC works in Moscone because they cap the number of attendees at 5,000.  VMworld 2014 has 22,000 attendees.  Cisco Live 2014 had well over 20,000 as well.  Cramming four times the number of delegates into a cramped Moscone Center does not foster the kind of environment you want at your flagship conference.

The main keynote hall in Moscone North is too small to hold the large number of audience members.  In an age where every keynote address is streamed live, that shouldn’t be a problem.  Except that people still want to be involved and close to the event.  At both Cisco Continue reading

Do We Need To Redefine Open?

There’s a new term floating around that seems to be confusing people left and right.  It’s something that’s been used to describe a methodology as well as used in marketing left and right.  People are using it and don’t even really know what it means.  And this is the first time that’s happened.  Let’s look at the word “open” and why it has become so confusing.

Talking Beer

For those at home that are familiar with Linux, “open” wasn’t the first term to come to mind.  “Free” is another word that has been used in the past with a multitude of loaded meanings.  The original idea around “free” in relation to the Open Source movement is that the software is freely available.  There are no restrictions on use and the source is always available.  The source code for the Linux kernel can be searched and viewed at any time.

Free describes the fact that the Linux kernel is available for no cost.  That’s great for people that want to try it out.  It’s not so great for companies that want to try and build a business around it, yet Red Hat has managed to do just that.  How can they Continue reading

Maybe MU-MIMO Matters

As 802.11ac becomes more widely deployed in environments I find myself looking to the next wave and the promise it brings.  802.11ac Wave 1 for me really isn’t that groundbreaking.  It’s an incremental improvement on 802.11n.  Wave 1 really only serves to wake up the manufacturers to the fact that 5 GHz radios are needed on devices now.  The real interesting stuff comes in Wave 2.  Wider channels, more spatial streams, and a host of other improvements are on the way.  But the most important one for me is MU-MIMO.

Me Mi Mo Mum

Multi-user Multiple-Input Multiple-Output (MU-MIMO) is a huge upgrade over the MIMO specification in 802.11n.  MIMO allowed access points to multiplex signals on different channels into one data stream.  It accomplished this via Spatial Division Multiplexing (SDM).  This means that more antennas on an access point are a very good thing.  It increases the throughput above and beyond what could be accomplished with just a single antenna.  But it does have a drawback.

Single-user MIMO can only talk to one client at a time.  All the work necessary to multiplex those data streams require the full attention of a single access point for Continue reading